Mtn cancel contract as from November 2018

Wrote a review April 2019 and received phone call from mtn on 1 April 2019 promising this will be sorted out. Received invoice from mtn for R2425.65 today - contract still not cancelled. This is ridiculous as I'm trying to cancel from November 2018. No phone call or confirmation from mtn after 1 April 2019......nearly 2months again.